Absorption refrigeration



Patented May 19, 1936 GlennF. Zellhoefer, Bloomington, 111.

No Drawing. Application December 11, 1934,

Serial No. 756,980

2 Claims.

The present invention relates generally to a solvent material and a refrigerant mixture for absorption refrigerating machines, both of the two-fluid type and of the three-fluid type.

Inabsorption refrigeration there is required a solvent material adapted to remain liquid throughout the operation of the apparatus, and" a refrigerant material adaptedto have a liquid and a vapor phase in the cycles of operation,

adapted to be dissolved or absorbed in the 501- vent, adapted to be evaporated or boiled as a. vapor from the solvent mixture and from the solvent, and adapted to be condensed from thevapor to a liquid. Numerous refrigerants and numerous solvents are known, as well as successful combinations of these.

The two-fluid absorption machines have certain mechanical parts which may be omitted or which are not duplicated in three-fluid machines. In a three-fluid machine, there is in addition to the two-fluid mixture a body of insert gas which is always gas, and which does not to any substantial extent dissolve in any of the components of the two-fluid composition, or in mixtures thereof.

The present invention is directed to a new solvent for absorption refrigeration, and to combinations thereof with refrigerants.

A particular object of the invention is the use of trimethylene glycol diacetate as a solvent.

Another object is the use of a combination of said solvent with the refrigerant, dichloromonoiluoromethane. 1

Examples of the two-fluid apparatus in which the'new solvent material and the new combina; tion may be used is disclosed in my co-pending application Serial 'No. 651,306, filed January 12, 1933, or in my U. S. Patent No. 1,895,698, issued January 31, 1933. Other examples may readily be cited, and will be known to those skilled in the art.

The two-fluid apparatus above referred to briefly described, comprises a still .in which a liquid mixture of solvent and refrigerant is heated to distill away as a vapor the refrigerant material, a condenser wherein said vapor is condensed to a liquid state, an evaporator wherein the resulting liquid is vaporized at reduced pressure to produce refrigeration, and an absorber in which vapor of the refrigerant material containing added heat units (acquired in'the refrigerating process) is again dissolved the solvent material. Suitable heat exchanging and circulating means-are included, and automatic controls may be provided.

well above normal temperatures, such for example at 210 F. to 250 F.; and that the cooling unit operates at temperatures lower than normal, such as from F. to 50 F. Various parts of the apparatusdiffer in the prevailing temperatures and pressures, andboth pressure and The particular characteristicsofsuch a ma-- chine are that the still operates at temperatures temperature determinev the physicalstate of the free refrigerant material, whether gaseous or liquid, and determine the solubility relations between the refrigerant and the solvent material. Itv is, therefore, very important that the solvent and the refrigerant materials be physically adapt ed for use as individual materials in certain places and for certain functions, and thatthey be mu-' tually adapted for certain functions when they are in combination. Other qualities not essentialto refrigeration, but pertinent to practical usage, control. or limit the choice of solvent or refrigerant, such as odor, viscosity, heat capacity,

boiling point, freezing point, volatility, chemical stability, reactivity, corrosive action, inflammability, toxicity, etc. i

By considering the limitations herein set forth and suggested, I have been able to utilize trimethylene glycol diacetate as a solvent, for practical usage, in combination with the refrigerant, dichloromonofluoromethane, which is little known.

The new solvent is herein named'as trimethylene glycol diacetate; however, -'in order to leave no doubt as to its identity, its structural formula is herein given:

CHsCOOCHzCHzCHzQCOCI-Is.

The refrigerant herein specified is dichloromonofiuoromethane. However, in order to leave no doubt as to itsidentity, its structural formul is herein given:

CHCIzF.

In the accompanying claims, the invention is set forth as a combination useful inabsorption refrigeration. It is to be understood that a simple adulteration of the new solvent in its pure form, either by reason of commercial impurities, or by addition of lesser quantities of other material, useful also as solvent, is permitted, and such a composition is intended to fall within the scope of the present invention. I

The solvent herein specifically claimed is covered generically in applicant's co-pending 2 V .8 7 application Serial No; 17,064, tiled April 18, 1935. 2. A refrigerant mixtureior the absorption type What I claim is: V of refrigeration apparatus consisting of trimethyl- 1. A refrigerant mixture for theabsorption ene glycol diacetate as the essentially predomi-, type of refrigeration apparatus consisting of nant solvent, and a volatile chemically stable 5 trimethylene'giycol diacetate as the essentially halogenated hydrocarbonreirigerant soluble in 6' predominant solvent, and dichloromonofl uoro said solvent. i g a methane as a r f 1s a t-- GLENN r. ZEILHOEFER. a 

